Barkai A I
J Neurochem. 1981 Jan;36(1):317-20. doi: 10.1111/j.1471-4159.1981.tb02414.x.
The quantitative contribution of glucose to the biosynthesis of lactosyl-ceramide and other glycosphingolipids was studied in the adult rat brain in vivo using a semicompartmental model. Half-lives of glucose carbon in both the total carbon pool and the carbohydrate residue of the lipid were calculated. In all glycolipids the half-life of carbohydrate units was six to eight times shorter than the half-life of carbon in the total carbon pool of the same lipid. This carbohydrate half-life appears to be closely related to the turnover rate of the glycolipid. The shortest carbohydrate half-life (2.2 days) was obtained for lactosyl-ceramide followed by gangliosides, galactosyl-ceramides, and sulphatides. The results indicate that lactosyl-ceramide may serve as a branch point for the biosynthesis of cerebral gangliosides in vivo, rather than occur as a breakdown product of more complex molecules.
利用半房室模型在成年大鼠脑内对葡萄糖在乳糖基神经酰胺及其他糖鞘脂生物合成中的定量贡献进行了研究。计算了脂质总碳库和碳水化合物残基中葡萄糖碳的半衰期。在所有糖脂中，碳水化合物单元的半衰期比相同脂质总碳库中碳的半衰期短6至8倍。这种碳水化合物半衰期似乎与糖脂的周转率密切相关。乳糖基神经酰胺的碳水化合物半衰期最短（2.2天），其次是神经节苷脂、半乳糖基神经酰胺和硫苷脂。结果表明，乳糖基神经酰胺可能是体内脑神经节苷脂生物合成的一个分支点，而不是更复杂分子的分解产物。
